13... e8c8 The king goes to the wrong side of the board. More than anything, this is a positional mistake: White's attack is simply much faster. 14. c1d2 The human reaction, simply preparing b4-b5 and mate. 14... c8b8 After castling queenside, Kb8 is the first move that should be considered. 15. b3b4  15... d8c8 